METHYLFOLATE EXHIBITS A NEGATIVE IN-VITRO INTERACTION WITH IMPORTANT DIETARY METAL-CATIONS

Methylfolate is an important dietary micronutrient essential for cell maturation and replication. Using HPLC with electrochemical detection we have shown that, at approaching neutral pH, anionic methylfolate co mplexes with metal cations leading to either oxidative degradation or possibly precipitation, the order of the effect being Zn2+>Ca2+ simila r or equal to K+>Mg2+ similar or equal to Na+. Equimolar Zn2+ and Naenhance methylfolate decay 33.3- and 7.2-fold, respectively, when comp ared to the decay in water alone. This effect does not occur in the pr esence of reduced glutathione or at mildly acid pH. These results may have important implications in vivo, particularly with respect to the bioavailability of dietary and pharmacological forms of the vitamin.